Tubbs R Shane, Kelly David R, Humphrey E Rita, Chua Gina D, Shoja Mohammadali M, Salter E George, Acakpo-Satchivi Leslie, Wellons John C, Blount Jeffrey P, Oakes W Jerry
Section of Pediatric Neurosurgery, University of Alabama at Birmingham and Children's Hospital Birmingham, Alabama 35233, USA.
Clin Anat. 2007 May;20(4):382-6. doi: 10.1002/ca.20334.
There is minimal information in the literature regarding the tectorial membrane. Further, information in the literature regarding the anatomy and function of this structure is often contradictory. We performed the current study to elucidate further this structure's detailed anatomy, function, and histology. Thirteen adult cadavers underwent dissection of their tectorial membranes and detailed observations and measurements were made of them. Ranges of motion of the craniocervical junction were performed before and after transection of this structure. Histological analysis was performed on all membranes. The tectorial membrane was found to attach much more superiorly than previously described and was found to be firmly adherent to the cranial base and body of the axis but not to the posterior aspect of the odontoid process. The mean thickness of this membrane was found to be 1 mm. Flexion of the head made the tectorial membrane fully taut at 15 degrees and extension made it fully taut at 20 degrees; however, there was a buckling effect (redundant tectorial membrane) noted at the level of the odontoid process in extension. With the alar and transverse ligaments cut and with flexion of the head, the middle portion of this membrane was stretched over the odontoid process, thus acting as a "hammock" that inhibited the odontoid process from moving posteriorly. The tectorial membrane did not limit cervical flexion per se but rather helped to insure that the odontoid process did not impinge into the cervical canal. Lateral flexion was not found to be limited by this structure. Histologically, parallel collagen fibers with spindle-shaped fibrocytes were observed within this membrane and near its attachment to the posterior axis, the collagen fibers were noted to be more homogenous with larger non-spindled fibrocytes. At the cranial attachment of the tectorial membrane, multiple calcified areas were noted that interdigitated with the underlying bone. Also near this cephalic bony attachment, there was an increase in the number of elastic fibers, which were found running parallel with the surrounding Type III collagen fibers. The tectorial membrane was found to attach much more superiorly than previously described. We would propose that the tectorial membrane provides for a second line of defense, preventing the odontoid process from compressing the spinal cord and by doing so, secondarily limits movement of the craniocervical juncture. This hypothesis is strengthened by the finding of many elastic fibers in the tectorial membrane. To our knowledge, our study is the first to perform a detailed histological analysis of the tectorial membrane. We hope that these data are useful to the clinician who investigates this ligament of the craniocervical region.
关于盖膜的文献资料极少。此外，文献中关于该结构的解剖和功能的信息往往相互矛盾。我们进行了本研究，以进一步阐明该结构的详细解剖、功能和组织学。对13具成年尸体的盖膜进行了解剖，并对其进行了详细的观察和测量。在切断该结构前后，对颅颈交界的活动范围进行了检测。对所有的膜进行了组织学分析。发现盖膜的附着位置比之前描述的更高，并且牢固地附着于颅底和枢椎体，但不附着于齿突的后方。该膜的平均厚度为1毫米。头部前屈时，盖膜在15度时完全绷紧，后伸时在20度时完全绷紧；然而，在后伸时，在齿突水平处发现有褶皱效应（盖膜冗余）。切断翼状韧带和横韧带并使头部前屈时，该膜的中间部分在齿突上伸展，从而起到“吊床”的作用，抑制齿突向后移动。盖膜本身并不限制颈椎前屈，而是有助于确保齿突不会侵入椎管。未发现该结构限制颈椎侧屈。组织学上，在该膜内及其与后轴附着处附近观察到平行的胶原纤维和梭形纤维细胞，在靠近后轴附着处，胶原纤维更均匀，纤维细胞更大且非梭形。在盖膜的颅骨附着处，发现多个钙化区域与下方的骨相互交错。同样在这个头部骨性附着处附近，弹性纤维数量增加，发现它们与周围的III型胶原纤维平行排列。发现盖膜的附着位置比之前描述的更高。我们认为盖膜提供了第二道防线，防止齿突压迫脊髓，从而间接限制颅颈交界的运动。盖膜中发现许多弹性纤维这一发现支持了这一假设。据我们所知，我们的研究是首次对盖膜进行详细的组织学分析。我们希望这些数据对研究颅颈区域该韧带的临床医生有用。
